Continuous time linear capacitive digital step attenuator

A digital step attenuator (DSA) includes a switch control circuit which receives the attenuated signal output by the DSA from a buffer and generates a tracked control signal for switches within the DSA. Some switch control circuits include a capacitor coupled to receive the buffered signal, a supply voltage, and a switch control logic sub-circuit for each switch. Each switch control logic sub-circuit receives a control signal, for either the gate or the bulk terminal of the switch, and generates the tracked control signal. In other embodiments, switch control circuits include a complementary MOSFET switching device coupled to receive a control signal, and a capacitor coupled to receive the buffered signal, both of which are connected to an output terminal for the tracked control signal. In those embodiments, the DSA includes a switch control circuit for each switch connected to the DSA output.